A frenulum (or frenum, plural: frenula or frena, from the Latin frēnulum, "little bridle", the diminutive of frēnum[1]) is a small fold of tissue that secures or restricts the motion of a mobile organ in the body.

Penile tissue: The word frenulum on its own is often used for the frenulum of prepuce of penis or frenulum preputii penis, which is an elastic band of tissue under the glans penis that connects to the prepuce, or foreskin to the vernal mucosa, and helps contract the prepuce over the glans.